1. Field of the Invention
The present invention relates to an insert cutter such as a face milling cutter and a side milling cutter, and particularly to a cutter which is hardly subjected to chattering.
2. Prior Art
Generally, when an insert cutter such as a face milling cutter is used to process a workpiece, each of the cutter inserts mounted on a cutter body engages the workpiece and disengages therefrom as the cutter body rotates, to result in an interrupted cutting. Therefore, the cutter body may be subjected to such impact force as to cause chattering, so that the cutter inserts may be susceptible to chipping. In view of the foregoing, an insert cutter which is hardly subjected to chattering has long been desired.
FIG. 1 shows one conventional face milling cutter which comprises a cutter body 100 having an axis O of rotation therethrough and a plurality of cutter inserts 102 releasably mounted on a periphery of the cutter body 100 at its forward end, the cutter inserts 102 being circumferentially spaced from each other with unequal central angles, as designated at .theta..sub.1 and .theta..sub.2. Each of the cutter inserts 102 includes a plurality of main and auxiliary cutting edges 104 and 106, and is disposed so that one of the auxiliary cutting edges 106 thereof is indexed in its end cutting position while one of the main cutting edges 104 thereof is indexed in its peripheral cutting position with prescribed radial, axial and corner angles.
In the face milling cutter described above, the indexed main cutting edge 104 of each cutter insert 102 carries out roughing while the indexed auxiliary cutting edge 106 thereof carries out finishing, and therefore a smooth finished surface can be obtained. Further, inasmuch as the plurality of cutter inserts 102 are spaced circumferentially of the cutter body 100 with the unequal central angles .theta..sub.1 and .theta..sub.2, chips of unequal thicknesses are alternately produced during cutting operation. For this reason, the cutter body 100 is subjected to impact force of irregular levels at irregular periodic time intervals, and hence the cutter is prevented from being resonated with a machine tool to some degree. However, the face milling cutter has still been resonated with the machine tool, and therefore the cutter body 100 has not been sufficiently prevented from being subjected to chattering.